This invention relates to an engine warning signal system and, more specifically, to a warning signal system for an engine air intake system such as that used with a diesel engine.
The air intake system on a diesel engine lies at the heart of engine operation. It is essential to efficient operation as well as engine life that the air intake system function properly. The air intake system of a diesel engine includes a dry air cleaner for cleaning the air entering the engine. When the air cleaner becomes collapsed or plugged for any of a number of reasons flow of air is restricted which adversely affects operation of the engine. However, an even more dangerous condition exists when the air cleaner becomes damaged or torn or the intake system leaks such that air is entering the engine without being cleaned. Continued operation of the engine under these conditions can cause serious engine damage.
Warning devices for indicating to an operator when the flow of air through the air cleaner has become restricted are known to the art. One such device is a gauge sold by Murphy Special Products Company which includes an electrically actuable warning circuit actuable by movement of an indicator needle to a predetermined vacuum level. Another is a pop-up valve sold by Donaldson Air Filter Company which gives a visual signal of the existence of a high vacuum in the system. However, there has not heretofore been available a warning system for warning an operator when the vacuum in the engine intake system either exceeds a predetermined maximum or falls below a predetermined minimum indicating a loss of air cleaning action. Specifically, there has not heretofore been available a warning system for warning an operator when the air cleaner is damaged or the air intake system is leaking such as because of a loose clamp or a hole in the piping.
Accordingly, it has been among the principal objects of this invention to provide a system for warning an operator when the vacuum in a system either exceeds a predetermined maximum indicating engine inefficiency or falls below a predetermined minimum indicating a problem which could cause serious engine damage.
It has been a further object of the invention to provide a system which is relatively simple for use in pneumatic systems such as an air intake system of a diesel engine.
Another object of the invention has been to provide a relatively simple, electrically operated warning system for a diesel engine which may include visual or audible warning signals and which may include electrically operated means for restricting engine operation on an unexpected loss of vacuum to prevent damage to the engine.